Question

If for a binomial distribution b(n, p) mean = 4 and variance = 4/3, the probability, P(X ≥ 5) is equal to _______ 

(a) (2/3)⁶ 

(b) (2/3)⁵ (1/3) 

(c) (1/3)⁶ 

(d) 4(2/3)⁶

Answer 1

(d) 4(2/3)⁶

np = 4, npq = 4/3 ⇒ q = 1/3 and p = 2/3

n = 4/p = 4/(2/3) = 6